Laminaria japonica extract inhibits VEGF-induced angiogenesis via binding with VEGF and regulation of VEGFR2 signaling pathway

Laminaria japonica (LJ) is a common seaweed, which has been widely used as functional food and medicine, but its pharmaceutical activities in angiogenic regulation are unclear. Here, different lines of studies provide evidence to the suppressive effects of LJ extract in VEGF-medicated angiogenic function. In cellular level, LJ extract significantly inhibited VEGF-mediated endothelial cell proliferation, migration, invasion and tube formation. For in vivo verification, LJ extract suppressed the VEGF-induced formation of sub-intestinal vessels in zebrafish embryo model. In signalling cascades, LJ extract decreased the amount of phosphorylated VEGF receptor-2, as triggered by VEGF, and subsequently some key related downstream elements were obviously inactivated. In parallel, NO production and ROS formation, as induced by VEGF, were significantly attenuated. Thus, these preclinical findings promoted the possible development of LJ extract as a potential therapeutic agent for prevention and clinical treatment of angiogenesis-related diseases.